Anxious business-school applicants have something to add to their to-do list: preparation for the new "integrated reasoning" section of the GMAT.

Although the new section was initially announced a year and a half ago, the Graduate Management Admission Council has offered scant details about what questions will look like and how they will be scored. With registration for the new test starting this month, many students are wringing their hands. Some test-prep experts say they may even see a rush of applicants wanting to take the test in the next few months just to avoid the new section, which won't appear on the exam until June.

The idea behind the "integrated reasoning" unit—which will be added to the existing verbal, quantitative and analytical writing sections—is to gauge how well applicants can extract and analyze complex data. The change comes as schools fall under increasing pressure from corporate recruiters to introduce more data-driven courses to better prepare students for the challenges they'll face after graduation.

"You're much more likely to have to analyze an integrated set of data than you are to do a geometry problem" in business school, says Andrew Mitchell, director of pre-business programs at Washington Post Co.'s Kaplan Test Prep. Geometry will still be covered within the GMAT's existing quantitative section.

So far, the council has published just four sample integrated-reasoning questions. One shows a table of data regarding flight traffic at various airports and asks the test-taker to determine relative passenger volume, flight landings and takeoffs at specific locations. Another question shows a scatter plot of ocean and air temperatures taken at a fixed location over the past year and asks test-takers to determine relationships between the two.

Many schools say GMAT scores, along with academic transcripts, are helpful predictors of how students will perform once they arrive on campus, but they are hopeful that the new section will provide an even more relevant data point.

"It's a step in the right direction," says Peter Zemsky, deputy dean of degree programs at INSEAD. Zemsky says that given the speed with which complicated decisions must be made in the business world, it's important to test applicants for such skills.

Still, admissions officers say they'll need at least a year before they know how to read results from the new section, as they see how test-takers progress through their first classes.

The test is still just a part of the total application package, which also includes interviews, references, essays and undergraduate transcripts.

Many admissions officers lament that students put too much emphasis on their GMAT scores, at the expense of other parts of their applications. "It doesn't matter what we say, applicants are going to stress out about the GMAT because it's (a) controllable, and (b) comparable," says Derrick Bolton, assistant dean and director of M.B.A. admissions at Stanford Graduate School of Business.

Data reflect that attitude: Admissions-consulting firm Veritas Prep found in a client survey that applicants already spend 71 hours preparing for the GMAT, but just 28 hours writing their essays and nine hours preparing for interviews.

The figure for test-prep likely will increase once the new version launches, say testing experts.